In currently available systems, the objective of high-speed uplink packet access technology is to improve capacity and data throughput in the uplink direction and reduce the delay in dedicated channels. The high-speed uplink packet access technology introduces a new transmission channel, an enhanced dedicated channel, which improves the implementation of the physical layer and the media access control layer, and makes the uplink data rate capable of reaching up to 5.6 MBPS theoretically. The high-speed uplink packet access technology retains the property of soft handover, and as to a terminal, there is an activation set of the enhanced dedicated channel. In the activation set of the enhanced dedicated channel, a cell received by a terminal from a node B, which is absolutely authorized to schedule, is referred to as service enhanced dedicated channel cell, and the corresponding radio link (that is, a radio link in this cell) is referred to as service enhanced dedicated channel radio link. In the activation set of the enhanced dedicated channel, a relatively authorized cell set which can be accepted and merged by the terminal is referred to as a service enhanced dedicated channel cell set, which at least includes the service enhanced dedicated channel cell. And, the corresponding radio link set (that is, a set of individual radio links in each cell) is referred to as service enhanced dedicated channel radio link set. In the activation set of the enhanced dedicated channel, a cell which does not belong to the service enhanced dedicated channel cell set is referred to as a non-service enhanced dedicated channel cell, and the corresponding radio link (that is, a radio link in this cell) is referred to as non-service enhanced dedicated channel radio link.
With the development of the technology, the dual-carrier high-speed uplink packet access technology (this technology enables the terminals to send data on two carriers with the high-speed uplink packet access technology, thus doubling the uplink data rate) is expected to be introduced into currently available systems. One of the dual carriers which includes a high-speed dedicated physical control channel, is referred to as the main carrier, and the other one thereof is referred to as the subordinate carrier. As to one terminal, each layer of carrier in the dual-carrier has its own independent enhanced dedicated channel activation set. At the layer of frequency of the subordinate carrier, in the activation set of the enhanced dedicated channel of the subordinate carrier, the node B to which the service enhanced dedicated channel radio link of the subordinate carrier belongs is referred to as service node B, and the other nodes B are referred to as non-service node B.
The service node B controls the activation and deactivation of the subordinate carrier. The service node B notifies the terminal of the activation and deactivation of the subordinate carrier via an air interface order. In the situation of subordinate carrier activation, the terminal confirms to the service node B that this air interface order is received, and carries out synchronization in individual cells of the activation set of the enhanced dedicated channel of the subordinate carrier. After having detected that the synchronization of subordinate carrier service cells by the terminal is successful, the service node B reports radio link restoration to the radio network controller.
Under such control mode of the service node B controlling the subordinate carrier activation and deactivation, there exists the problem that the terminal carries out synchronization in a cell in the activation set of the enhanced dedicated channel of subordinate carrier under non-service node B. As to this terminal, if there is only a cell for receiving and sending subordinate carrier in the terminal context of non-service node B but no cell for receiving and sending main carrier, then the non-service node B has no phase reference difference of a main/subordinate carrier physical layer obtained in the action of the terminal receiving and sending on the main carrier frequency layer. And it will cause: when the terminal carries out synchronization in a cell in the activation set of the enhanced dedicated channel of subordinate carrier under non-service node B, the non-service node B and the terminal will need bigger search windows to detect the synchronization and the synchronization time delay is increased, and the inter-cell interference is also directly increased, thus affecting cell capacity and coverage.